corresponding L01DSYS function was executed. If the storage occupied by
the named segment was beyond the defined virtual machine storage size,
that storage is no longer addressable by the virtual machine. When a PUBGESYS function is executed for a segment that was loaded in
nonshared .ode, the storage area is cleared to binary zeros. If PUBGESYS is invoked for a named segment that was not previously loaded
via L01DSYS, the request is ignored. 1 condition code of 0 in the PSW indicates successful completion. 1 condition code of 1 in the PSW indicates that the named segment was not found in the virtual machine. 1 condition code of 2 in the PSI and a return code of 44 in the By
register indicate that the named segment either does not exist or was not previously loaded via the L01DSYS function. When the FIHDSYS function is executed, CP checks that the named segment exists and that it has not been loaded previously. 1 condition code of 0 in the PSI indicates that the naaed segment is
already loaded. The address at which it was loaded is returned in the
register specified as Bx and its highest address is returned in the By
register. 1 condition code of 1 in the PSi indicates that the named segment exists but has not been loaded.. In this case, the address at which the named segment is to be loaded is returned in the register specified as Bx and the highest address of the named segment is returned in the By register. 1 condition code of 2 in the PSi indicates the FIIDSYS function did
not execute successfully. Exaaine the return code in the By register to
deter.ine the error that occurred. Betu:t1! 44 177 !hl!aning Hamed-segment does not exist Paging I/O errors £2de == Virtyal lachine FacilitI The DIIGBOSE code 1'68' is used by a virtual machine to initiate a
subfunction of the Virtual !achine Communication Pacility (V!CP). The general register specified as Bx contains the virtual address,
doubleword aligned, of a parameter list (VSCPIB!). One of the entries
in this parameter list is a sub function code, specifying the particular
request being initiated. The subfunctions and their codes are:
CP Introduction 1-69

Subfunction AUTHORIZE UNAUTHORIZE SEND SEND/RECV SENDX RECEIVE CANCEL REPLY QUIESCE RESUME IDENTIFY REJECT Code i'oooo' X'0001' X'0002' X'0003' X'0004' X'0005' X'0006' 1'0007' X'0008' X'0009' X'OOOI' X'OOOB' A description of all the fields of the VMCPARM is contained in the VM/370 Programmer's The general register specified as Ry will
upon completion of DIAGNOSE X'68' or the Tbp rp+nrn §yide. contain the return code
detection of an error
in the Vft/370 Svstem Rx and Ry can be any general register, RO through R15. They may also
be the same register. == Load 380Q Naaed System Into Virtual DIAGNOSE code 1'14' allows a virtual machine to load a 3800 named systea into virtual storage beginning at a specified virtual address and to
take a copy of an image library and save it in a specified named systea. A naaed system is one that contains 3800 character arrangeaent tables, copy modifications, and file control blocks (PCBs). These can be
referenced by name, and the data can be obtained when the file
referencing them is about to print on a 3800 printer. The new data in
the named system is used to load into the 3800 the next time NlftED SYSTEK is specified as the IMIGELIB paraaeter in a STIRT command for a 3800 printer.
At system generation time, the NAME3800 macro instruction establishes
the nalle of the 3800 system in the D!KSBT aodule. The active naaed system for a particular 3800 printer will be in its RDEVBLOK.
The GENIftAGE command creates the image library in virtual storage.
This is done by interfacing with the OS IEBI!AGE utility program (DMKIftG). The IMAGELIB command saves the image library and issues the DIAGNOSE code 1'14' to establish the named system. When using DIAGNOSE code 1'14', the registers specified by the user
as Rx and Rx.1 must contain the eight-character nalle of the system desired, left-justified and padded with trailing blanks.
The register specified by the user as Ry must contain the virtual
address at which to start loading or saving the storage image of an illage library.
The register specified by the user as Ry+1 must contain a one-byte
code in the high-order byte indicating the function to be performed as
follows: X'OO' - LOAD operation X'04' - SAVE operation 1-70 IBM VM/370 System Logic and Problem Deteraination--Volume 1